How to Choose the Right BMS
How to Choose the Right BMS?
1. Continuous Discharge Current
The BMS continuous discharge current rating must exceed your device's maximum continuous operating current by a 20%–30% margin.
For example: if your load draws 30A continuously, choose a BMS rated at least 40A.
2. Peak Current
For momentary high-current events (e.g., motor startup), the BMS peak current rating should be 2–3x the continuous current, and its duration must cover the device's startup time.
For example: a 40A BMS typically supports a peak of ~80–120A for a few seconds to handle motor startup surges.
Battery Connection Methods
- Series Connection: Total pack current = single cell current. Current is identical throughout a series circuit.
- Parallel Connection: Total pack current = single cell current × number of parallel cells.
- Series-Parallel Combination: Total pack current = single cell current × number of parallel cells per block.
Example — A 20S Battery Pack with 3 Parallel Cells per Block
For a battery pack built with 20 cells in series and 3 cells in parallel per block:
- 3 parallel cells per block means the pack current = single cell current × 3
- If each cell delivers 20A, total pack current = 20A × 3 = 60A
- Recommended BMS: rated at least 80A (with 20%–30% margin)
- Recommended usable load = 70–80% of BMS rated current for long-term reliability
- Peak protection current activates for a few seconds to handle motor startup or surge loads
BMS Selection by Protection Current
| Protection Current | Typical Use Case | Common Applications |
|---|---|---|
| 40A | Light load | Small e-bikes, electric scooters, portable power stations |
| 60A | Light to medium load | E-bikes, electric skateboards, backup power systems |
| 80A | Medium load | High-performance e-bikes, energy storage systems |
| 100A | Medium to high load | Electric vehicles, industrial battery packs |
| 120A | High load | High-voltage e-bikes, EVs, large energy storage |
| 150A | High load | Large EVs, commercial energy storage |
| 200A | Very high load | Heavy-duty EVs, large-scale energy storage |
| 300A | Ultra high load | Industrial-grade systems, large battery arrays |
Connecting to an Inverter? Read This First
If you plan to connect your BMS to an inverter for off-grid solar systems or home energy storage (ESS), please note:
- ✅ CAN communication is required for most inverter brands. You must choose a BMS with CAN support — i.e., the HC or HCR version.
- ✅ For off-grid solar or home ESS applications, we strongly recommend the dedicated JKBMS Inverter BMS series, which is purpose-built for inverter integration.
- ⚠️ Standard BMS versions without CAN are not compatible with inverter communication protocols.
Supported Inverter Brands & Protocols
The following list covers the mainstream inverter brands currently supported by JKBMS. If your inverter brand is not listed, please contact us.
| Brand | Protocol | Communication | Notes |
|---|---|---|---|
| Deye | Low-voltage hybrid inverter CAN protocol | CANBUS-500K | Battery Setup Menu → Lithium; Advanced Function → BMS_Err_Stop |
| PYLON | PYLON CANBUS Protocol V1.2 / Low voltage RS485 | CANBUS-500K / RS485-9600 | — |
| Growatt | CAN Bus REV_05 / RS485 ESS Protocol V2.01 | CANBUS-500K / RS485-9600 | Set 05 to LI; Set 36 to 1 for CAN or 51 for RS485 |
| Victron | CAB-BUS BMS Protocol 201707 | CANBUS-500K | Via Cerbo GX |
| INVT | CAN Bus Protocol V1.02 | CANBUS-500K | BD5KTL-RL1 |
| GoodWe | LV BMS Protocol V1.7 | CANBUS-500K | GW5000-ES-20; Select GoodWe → SECU-A5.4L×1 |
| SMA | FSS-ConnectingBat-TI-en-10 V1.0 | CANBUS-500K | — |
| Voltronic | Voltronic Power Inverter & BMS 485 Protocol V0 | RS485-9600 | Long press SET → Set 05 to LIB |
| SRNE | PACE BMS Modbus Protocol for RS485 | RS485-9600 | Set 39 to BMS; Set 32 to BMS; Set 33 to WOW |
| MUST | — | — | — |
| SOFAR | — | — | — |
📌 This compatibility list will be continuously updated. Don't see your inverter? Contact us.
Standard Features (All JKBMS Smart BMS)
💡 Note: The features below apply to the Smart BMS series. The JKBMS Inverter BMS is a fully integrated solution with all features built-in — see the dedicated Inverter BMS section above.
- ✅ LCD Bluetooth status indicator
- ✅ APP Bluetooth remote operation & monitoring
- ✅ Battery capacity calculation (SOC)
- ✅ High-precision voltage acquisition (±3mV)
- ✅ High-precision current acquisition
- ✅ LCD display interface support
- ✅ Accurate time logging
Protection Features
- ✅ Charge overcurrent protection
- ✅ Charge overvoltage protection
- ✅ Charge over-temperature protection
- ✅ Low-temperature protection during charging
- ✅ Discharge overcurrent protection
- ✅ Discharge undervoltage protection
- ✅ Discharge over-temperature protection
- ✅ Short-circuit protection
Optional Add-ons (Smart BMS only — not applicable to Inverter BMS)
The following features are available on selected Smart BMS models or via custom order. Please contact us to discuss your specific requirements:
- ✅ RS485 communication
- ✅ CAN communication
- ✅ Parallel expansion function
- ✅ Alarm function
- ✅ Heating function
- ✅ ACC detection function
JKBMS Inverter BMS — Fully Integrated Features
The JKBMS Inverter BMS is purpose-built for inverter and ESS integration. All the following features are fully integrated — no add-ons required:
- ✅ Active cell balancing
- ✅ Bluetooth connectivity
- ✅ NTC temperature sensing
- ✅ RS485 communication
- ✅ CAN communication
- ✅ Display interface
- ✅ Heating function
- ✅ Dry contact (alarm output)
- ✅ Charge overvoltage protection
- ✅ Overcurrent protection
- ✅ Short-circuit protection
- ✅ Battery parallel current limiting
- ✅ Discharge pre-charge
Need help choosing? Contact us with your battery specs and we will recommend the right model.